Spacing devices for overhead wires



Dec. 1, 1959 J. E. GILL ETAL 2,915,580

SPACING DEVICES FOR OVERHEAD WIRES Filed July 15, 1957 2/ 23 ll Inventor:

Z 1.166" E Gill dwa rd M F/efc/ er By ,g/JMMM M A Home ys United States Patent SPACN G DEVICES FOR OVERHEAD WIRES John Edward Gill, Brentwood, and Edward William Fletcher, 'Surbiton, England, assignors to Balfour, Beatty & Co. Limited, London, and Andre Rubber Company Limited, Surbiton, England, both British companies, jointly Application July 1'5, 1957, Serial No. 671,804 Claims priority, application Great Britain August 2, 1956 Claims. 01. 174-43 When two or more overhead wires hanging between supports run closely together and it is necessary to ensure that they do not come into contact with each other, spacing devices are fixed between the wires at intervals along their length.

Such spacing devices are used in particular in overhead electric transmission systems to maintain the spacing bet-ween pairs of conductors which are required to carry one phase.

Spacing devices have been used which consist of a bar with a clamp at each end. One conductor is carried in each clamp and the clamps have usually been pivoted on the bar about an axis perpendicular to the longitudinal axis of the conductor so that the conductors can be moved longitudinally relative to each other through a limited distance. These spacing devices have not, however, proved satisfactory in practice and cause serious wear of the conductors at the places Where they are clamped. Some spacing devices themselves have also been subject to deterioration.

It has now been found that the deterioration of both the conductors or other wires and the spacing device itself can be greatly reduced if, in accordance with the present, invention, the spacing device comprises a spacer member and a number of clamps spaced apart on the spacer member, each clamp holding a body or strip of rubber or other material having a rubber-like resiliency which is engageable around or partly around a wire so that, by tightening the clamp, the body or strip is compressed against the wire to maintain the wire firmly in position within the clamp.

The body or strip of rubber or other material having a rubber-like resiliency is preferably sufiiciently large to permit a small angular deflection of the wire to take place within the clamp and thus to allow relative longitudinal movement to take place between the wires held by the spacing device.

The device is most frequently required to maintain a space between two wires which hang side-by-side and when this is the case, the device comprises a bar with a clamp at each end. The resilient material, when in the form ofa body, has a hole of a cross section suitable for the section of the wire to be clamped in it and preferably the external shape of the body is such that the body forms a circular bush. The bush is split to enable it to be readily placed in position around the wire. The body or strip may be made of semi-conducting synthetic elastomeric material so that when the spacing device is in use with electric cables thespacer member is in electrical contact with the cables and static electrical charges are prevented from building up on it.

The body of resilient material, at least partially absorbs the vibrations transmitted from the wire clamped within it and prevents or reduces the transmission of these vibrations through the spacing device. Thus the deterioration of the cable and also of the spacing device is greatly reduced.

2,915,580 Patented Dec. 1, 1959 An example of a spacing device constructed in accordance with the invention for spacing apart two electric cables is illustrated in the accompanying drawings, in which:

Figure 1 is a diagrammatic perspective View of a pair of overhead cables suspended from two supports, showing two spacing devices in position on the wires;

Figure 2 is a perspective view of parts of the spacing device before assembly;

Figure 3 is a plan view of one part of the device shown in Figure 2;

Figure 4 is a longitudinal section on the centre line of the assembled device; and

Figure 5 is a cross section through the device as viewed in the direction of the arrows in Figure 4 on the line V-V.

The spacing device illustrated in the drawings is intended to space only two overhead electrical conductors, lying side-by-side, apart from each other. The device comprises a bar divided into two similar half cylindrical parts 1 and 2, one of which has an enlarged head 3 at one end and a similar head 4 at the other end, and the other of which has similar enlarged heads 5 and 6. The enlarged heads 3, 4, 5, 6 are formed with half circular grooves, 7, 8, 9 and 10 respectively. The two halves of the spacing device fit together as shown in Figure 4 and are located relatively to each other by a spigot 11 which projects from the part 1 and engages in a hole 12 in the part 2, and a similar spigot 13 which projects from the part 2 and engages in a hole 14 in the part 1.

The part 1 is formed at both ends with dovetailed grooves 15, 16 which coincide with similar grooves 17, 18 in the part 2 when the two halves of the device are placed together. The two halves of the device are held together by keys 19, 20 which fit in the grooves 15, 17 and 16, 18 respectively. The keys 19 and 20 are provided at one end with bent lugs 21, 22 and further similar lugs 23, 24 at their opposite ends. The lugs 23, 24 are bent over as shown in Figure 5, after the keys have been inserted so that they are locked in position.

To fix the spacing device in position on a pair of cables 25, 26, bodies of resilient material in the form of split bushes 27, 28 are placed around the cables 25, 26 respectively. The lower half of the device comprising the part 2 is then placed in position with the bush 27 located in the groove 9 and the bush 28 located in the groove 10. The upper half of the device comprising the part 1 is then placed in position and locked by the keys 19, 20, as described above.

The bushes 27, 28 are initially of a slightly greater external diameter than the bores formed by the grooves 7, 9 and 8, 10. Thus when the two halves of the device are assembled together, the bushes 27, 28 are slightly compressed by the enlarged heads 3, 4 and 5, 6 which form two pairs of jaws and are firmly anchored in position. The bushes 27, 28 are provided with end flanges 29 to locate them in their axial direction in the bores formed by the grooves 7, 8, 9 and 10.

The bushes 27, 28 may alternatively be made with an external diameter equal to that of the bores formed by the grooves 7, 9 and 8, 10 but with an internal diameter less than that of the cables to be held within them. When the bushes are placed around the cables they are expanded and are then compressed again by the heads 3, 4 and 5, 6. As a further alternative the external diameter of the bushes may be made larger than the bores and also the internal diameter may be made less than that of the bushes.

In this example the two halves of the spacing device comprising the parts 1 and 2 with the parts which are formed integrally with them are formed as light metal die castings. As will be seen, when the device is assembled, its external profile is smoothly rounded so that any losses from the two electrical conductors by corona discharge which might occur into the surrounding atmosphere from any sharp arrises, is reduced.

The bushes 2'7, 28 are made of neoprene. In the example illustrated, the circular bar formed by the two parts 1 and 2 is one and a half inches in diameter, the bores formed by the semi-circular grooves 7, 9 and 8, 10 are at twelve inch centres and the diameter of the bores is one and five-sixteenths of an inch. The external diameter of the bushes 2'7 and 23 is 1.332 inches and the internal diameter .76 inch.

Somewhat thinner bushes having a wall thickness of the order of one sixteenth of an inch may be used to hold a cable and will be effective if sufficiently cornpressed by the enlarged heads of the spacing device. Instead of being split as shown in the drawings, the bushes may be made in two separate halves and these halves may be bonded one to each of the enlarged heads 3, 4, 5 and 6.

Two of the devices are shown in position on the pair of cables 25, 26 in Figure l of the drawings, the cables being supported between two supports 30, 31.

The rubber bushes 27, 28 are sufficiently thick to allow the cables to take up positions slightly skew to the centre lines of the bores formed by the grooves 7, 8, 9 and 10, thus allowing a small relative longitudinal movement between the cables to take place. If it is necessary to enable a substantial relative longitudinal movement between the cables to take place, the enlarged heads 3, 4, S and 6 may be pivoted to the parts 1 and 2.

For spacing apart three or more cables, the resilient bushes may be held in clamps disposed around a ring shaped spacer member or, alternatively, the spacer member may have a number of arms equal to the number of cables and each arm has enlarged heads similar to the heads 3, 4, 5 and 6 forming a clamp.

We claim:

1. A device for spacing apart a pair of overhead cables suspended between supports, said device comprising a pair of bars having mating faces and each bar having two spaced dovetailed slots transversely to its length in its mating face, the bars being in parallel relationship with their slotted mating faces together, an enlarged head on each end of each of said bars bounded on one side by its mating face, each of said heads having a groove in said mating face extending transversely of the length of said bars, two dovetailed keys each fitting in a dovetailed slot in each of said bars, whereby said bars are locked together in a position in which pairs of said heads are adjacent each other, each pair of heads enclosing between them an opening formed by a pair of said grooves, and two bushes of material having a rubber-like resiliency, one for surrounding and gripping each of said cables, one bush being radially inwardly compressed in each of said openings and said compressed bushes urging said bars apart from each other and thereby forcing said dovetailed slots into close engagement with said keys.

2. In an overhead electrical transmission system, two supports, a pair of cables suspended between said supports and at least one spacer device for spacing said cables apart from each other fixed to said cables at a point spaced from said supports, said spacer device comprising a pair of bars having two mating faces and each bar having two spaced dovetailed slots transversely to its length in its mating face, the bars being in parallel relationship with their slotted mating faces together, an enlarged head on each end of each of said bars bounded on one side by its mating face, each of said heads having a groove in said mating face extending transversely of the length of said bars, two dovetailed keys each fitting in a dovetailed slot in each of said bars, whereby said bars are locked together in a position in which pairs of said heads are adjacent each other, each pair of heads enclosing between them an opening formed by a pair of said grooves, and two bushes of material having a rubber-like resiliency, each bush surrounding one of said cables and being radially inwardly compressed on to said cable in one of said openings, whereby said bushes maintain said cables firmly in position and urge said bars apart from each other and thereby force said dovetailed slots into close engagement with said keys.

3. A device for spacing apart a pair of overhead wires suspended between supports, said device comprising a pair of semi-cylindrical bars, each having two spaced dovetailed slots at right angles to its length, the bars being in parallel relationship with their slotted faces against each other, a hemispherical head on each end of each of said bars, each of said heads having a semicircular groove with its axis at right angles to said bars, two dovetailed keys each fitting in a dovetailed slot in each of said bars, whereby said bars are locked together in a position in which pairs of said heads are adjacent each other, each pair of heads enclosing between them a circular opening formed by a pair of said grooves, and two bushes of material having a rubber-like resiliency, one for gripping each of said wires, one bush being held compressed in each of said openings and said compressed bushes urging said bars apart from each other and there by forcing said dovetailed slots into close engagement with said keys.

4. In an overhead electrical transmission system, two supports, a pair of cables suspended between said sup ports and at least one spacer device for spacing said cables apart from each other fixed to said cables at a point spaced from said supports, said spacer device comprising a pair of semi-cylindrical bars, each having two spaced dovetailed slots at right angles to its length, the bars being in parallel relationship with their slotted faces against each other, a hemispherical head on each end of each of said bars, each of said heads having a semi-circular groove with its axis at right angles to said bars, two dovetailed keys each fitting in a dovetailed slot in each of said bars, whereby said bars are locked together in a position in which pairs of said heads are adjacent each other, each pair of heads enclosing between them a circular opening formed by a pair of said grooves, and two bushes of material having a rubber-like resiliency, each bush surrounding one of said cables and being inwardly compressed within one of said circular openings, whereby said bushes maintain said cables firmly in position and urge said bars apart from each other and thereby force said dovetailed slots into close engagement with said keys.

5. In an overhead electrical transmission system as claimed in claim 4, lugs at the ends of said dovetailed keys, said lugs projecting laterally beyond the edges of said slots to hold said keys in position.

References Cited in the file of this patent UNITED STATES PATENTS 770,278 Fletcher Sept. 20, 1904 1,988,150 Austin Ian. 15, 1935 2,363,405 Eichelberger Nov. 21, 1944 2,820,083 Hendrix Jan. 14, 1958 FOREIGN PATENTS 724,729 Great Britain Feb. 23, 1955 

